The present invention relates to an apparatus for thermogravimetry which automatically measures the weight changes of each of a plurality of samples, which weight changes depend on sample temperature when the operation of sample conveyance and the operation of thermogravimetry are alternately and automatically performed.
Thermogravimetric analysis in thermal analysis is a relatively old technique which began with the Honda type of thermobalance.
Even though the usefulness of thermogravimetric analysis is now widely known, thermogravimetry apparatus which can automatically measure a plurality of samples is relatively unknown. In conventional apparatus for thermogravimetry, as disclosed in Japanese Patent Application Laid Open No. 720331983, the following methods are used: the initial weight of a sample before thermal analysis is preliminarily measured by a worker with a chemical balance; or the weight output obtained when an empty sample container is set on an apparatus is used as a reference, and the variation of weight output obtained when a sample is loaded in the sample container is used as the weighed value.
When thermogravimetric analysis for a plurality of samples is automatically conducted, for example, samples are put in platinum sample containers in order to minimize staining of the apparatus which is caused when the samples are heated. Therefore, it is rather difficult to measure only the initial weight of samples. For example, in the case where about 50 samples are measured with a chemical balance, measurement with respect to one sample must be conducted once before and once after the sample is loaded in a sample container, and it is necessary to then determine the weight difference. Depending on the configuration of the samples, this can take about 2 hours in total. Since the samples must be manually loaded in the sample containers, it is impossible to measure a plurality of samples continuously and automatically.